1. Field of the invention
The present invention relates to an in-vehicle illuminating device, and more particularly, to an in-vehicle illuminating device suitably used for an in-vehicle illuminating system arranged in an in-vehicle instrument panel or the like.
2. Description of the Related Art
Heretofore, there has been known, as an in-vehicle illuminating device arranged in an in-vehicle instrument panel, for example, a device comprising a rod-shaped light guiding body and a luminous source, such as an LED (Light-Emitting Diode) arranged at an end of the rod-shaped light guiding body to guide luminous flux emitted from the luminous source from the first end of the rod-shaped light guiding body to the second end thereof.
In a case where such device is designed so that the luminous source is arranged coaxially with the rod-shaped light guiding body to emit luminous flux in parallel with a longitudinal direction of the rod-shaped light guiding body, however, there has been a problem that the in-vehicle illuminating device becomes too large in size as a whole in the longitudinal direction since the luminous source must be arranged adjacent to an end face of the end of the rod-shaped light guiding body in parallel therewith.
To address this problem, Japanese unexamined patent publication No. 2000-331522, for example, proposes arranging a luminous source so as to emit light to a direction orthogonal to a longitudinal direction of the rod-shaped light guiding body. However, according to this prior art, there has also been a problem that due to the rod-shaped light guiding body being orthogonal to the luminous flux emitted from the luminous source, it is difficult to efficiently guide the luminous flux emitted from the luminous source into the light guide, thus making it impossible to obtain a bright illuminating device.